The present invention relates to a releasing device for snow chains or anti-skid devices intended for mounting on the tires of vehicles.
When a vehicle travels on a road surface covered with snow, sleet or ice, its tires do not have a good grip and dangerous swerving or skidding of the vehicle can occur. To avoid these problems it is customary to use anti-skid devices, commonly called snow chains.
Snow chains, normally mounted on the driving wheels of the vehicle, bite into the snow and/or ice deposited on the road surface, increasing the tread traction and allowing the vehicle tires to achieve a good grip.
As is known, a snow chain generally consists of two side members (chains, flexible cables, steel wires, ropes or the like) which during use are closed in a ring on the inner face and the outer face of the wheel, respectively. These side members are connected by a series of chain portions variously disposed to achieve tread traction, the whole being completed by a tensioning device for said members, known as a tensioner.
Types of snow chains widely available on the market have an inner side portion consisting of an inner flexible ring that can be opened to allow widening thereof during the mounting operation, so that it can be applied to the inner face of the vehicle wheel. Said inner ring normally consists of a metal cable covered with a continuous or interrupted sheath.
Said known chains provide an inner fastening closure according to which one end of the cable of the inner ring is provided with a hollow elongated engaging means in which a portion thereof is able to receive a head provided at the other end of the cable, while another portion thereof is able to retain said head, a channel being provided which permits shifting of the cable along said engagement means, so that the head comes to be locked inside the locking portion.
This type of inner closure, though allowing easy locking of the ring portion, nevertheless presents some problems during removal.
The user, in order to remove the chains, is obliged to work from the inner side of the wheel. In fact he must find the closing device of the inner ring in the inner side of the wheel and manually carry out release of said device. This operation proves quite awkward, tiresome and complex. In fact the user must work in an uncomfortable position, is obliged to dirty his hands which inevitably come into contact with the tire and in addition has difficulty in finding the inner ring closing device which remains hidden on the inner side of the wheel. Consequently, said operation of removal of the chains proves excessively slow and tiresome.
Releasing devices are also known which provide operating means that can be operated from the outer side of the wheel to bring about release of the closing member of the inner ring. Said releasing devices have drawbacks due to the complexity of the closing member.
The object of the present invention is to eliminate the drawbacks of the prior art, providing a releasing device for snow chains that is safe, practical, easy to use, inexpensive and simple to make.
This object is achieved in accordance with the invention having the characteristics listed in appended independent claim 1.
Preferred embodiments of the invention will become apparent from the dependent claims.
The releasing device for snow chains according to the invention provides a closing device able to close the inner side portion of the chains as a ring and an operating device that acts on the closing device. The operating device can be operated from the outside of the tire by the user and provides a cable that acts on the closing device. Said cable is protected by means of two chains disposed alongside and parallel thereto and by means of crosspieces disposed transversally with respect to the cable and fixed to the links of the chain.
In this manner better stabilization and better functioning of the operating device are achieved.
Moreover the closing device has at one end of the cable of the inner ring a block containing a first tooth urged by elastic means to protrude externally on a seat so as to block a second tooth, fixed at the other end of the cable of the inner ring, and housed in the seat of the closing device. The cable of the operating device acts on a lever pivoted inside the closing device that makes the first tooth retract, so as to release the second tooth which can be extracted from the seat.
Such a device proves extremely simple and effective and allows perfect operation, reducing the risks of jamming.
Moreover, in the event of jamming of the operating device the possibility of releasing the snow chains is still ensured. In fact the shape of the second tooth and of the seat that receives it are such as to allow a rotation of the second tooth inside said seat so that the second tooth can be extracted from the seat even when the first tooth is not retracted inside the closing device.